ABSTRACT
BACKGROUND@#Repair of long-distance peripheral nerve defects remains an important clinical problem. Nerve grafts incorporated with extracellular vesicles (EVs) from various cell types have been developed to bridge peripheral nerve defects. In our previous research, EVs obtained from skin-derived precursor Schwann cells (SKP-SC-EVs) were demonstrated to promote neurite outgrowth in cultured cells and facilitate nerve regeneration in animal studies. @*METHODS@#To further assess the functions of SKP-SC-EVs in nerve repair, we incorporated SKP-SC-EVs and Matrigel into chitosan nerve conduits (EV-NG) for repairing a 15-mm long-distance sciatic nerve defect in a rat model. Behavioral analysis, electrophysiological recording, histological investigation, molecular analysis, and morphometric assessment were carried out. @*RESULTS@#The results revealed EV-NG significantly improved motor and sensory function recovery compared with nerve conduits (NG) without EVs incorporation. The outgrowth and myelination of regenerated axons were improved, while the atrophy of target muscles induced by denervation was alleviated after EVs addition. @*CONCLUSION@#Our data indicated SKP-SC-EVs incorporation into nerve grafts represents a promising method for extended peripheral nerve damage repair.
ABSTRACT
Objective To compare the clinical effect of two different kinds of wound dressing on postoperative skin reactions and phlebitis for PICC in critical patients. Methods A total of 313 PICC critical patients were divided into control group (157 cases) and treatment group (156 cases) by random digits table method. After PICC, the control group was attached to transparent dressing, the experimental group was attached to Mepilex, all of the patients were received routine nursing. The incidences of adverse effect, and the degree of local skin pruritus by Visual Analogue Scale(VAS) were compared in two weeks. Results The incidence of skin allergy, infection, and mechanical phlebitis were 24.20%(38/157), 10.83%(17/157), 18.47%(29/157) in control group and 7.69%(12/156),4.49%(7/156), 3.21%(5/156) in treatment group, and there were significant differences between two groups (χ2=13.99, 4.44, 18.83, P<0.01 or<0.05). The score of VAS in control group and treatment group were (4.84±1.29) points and (3.15± 1.82) points respectively, and the difference was statistically significant (t=8.66, P<0.01). Conclusions Application of Mepilex for PICC in critical patients can decrease the incidences of adverse effect, and increase the degree of comfort. It is worth utilizing widely in the clinic.
ABSTRACT
AIM:To investigate the role of B cells in CD45RB antibody-induced transplantation immune toler-ance.METHODS:Single cell suspension was made from the spleen of BALB/c nude mice disposed by CD45RB antibod-y, then mixed cultured with T cells of BALB/c mice and spleen cells of C57BL/6 mice.The Th1, Th2, Treg and Tm cells were monitored by flow cytometry during the culture process .The skin graft model was set up with B 6.μMT-/-mice as re-ceptors and BALB/c mice as donors.CD45RB antibody was intraperitoneally injected into the receptors after transplantation and then CD3+CD45RBhi cells were detected by flow cytometry .In another mixed lymphocyte culture , CD45RB antibody was added, and then B cells were isolated and injected into B6.μMT-/-mice through the tail vein.The heart transplanta-tion model was established with B 6.μMT-/-mice as receptors and BALB/c mice as donors, and then the survival and the migration of B cells to the thymus were observed .RESULTS:When T lymphocytes were co-cultured with B lymphocytes treated with anti-CD45RB monoclonal antibody (mAb) in vivo, the percentages of Th2 and Treg cells were up-regulated and Th1 cells were down-regulated, but Tm cells were not altered as compared with the control .In vivo without B lympho-cytes, anti-CD45RB mAb also down-regulated the expression of CD45RB in T lymphocytes.The reduction was faster and the percentage of CD3 +CD45RBhi T cells was not altered as compared with the control .The B lymphocytes treated with an-ti-CD45RB mAb in vitro prolonged the lifetime of receptor in heart transplantation model but failed to induce complete toler -ance.After recieving B cells treated with anti-CD45RB mAb and allogeneic heart transplantation , B cells migrated to the thymus in B6.μMT-/-mice.CONCLUSION:B lymphocytes play a definite role in the transplantation immune tolerance induced by anti-CD45RB mAb through their affection on T-cell subgroups and also in the central tolerance .However, the induction of immune tolerance can not only rely on B cells .
ABSTRACT
Objective:To investigate the effect of piggyBac transpon,as a carrier of four defined transcription factors Oct4,Sox2,Klf4 and c-Myc,in the reprogramming of mouse embryonic fibroblasts (MEFs)to induced pluripotent stem cells (iPSCs).Methods:The MEFs were isolated from Oct4-GFP fetal mice and transfected by piggyBac transposon with four factors (Oct4,Sox2,Klf4 and c-Myc).The morphological changes of clones were traced with microscope during the process of induction.The chromosomes were analyzed to evaluate the karyotypic variation of iPSCs.The mRNA expressions of Oct4, Nanog and FGF4 associated with embryonic stem cells (ESCs)in the iPSCs of mice were tested by RT-PCR;the protein expressions of SSEA-1,Nanog and Alkaline phosphatase in the iPSCs of mice were determined by flow cytometry,immunofluorescence and AP staining.The iPSCs were transplanted into the NOD-SCID mouse groin,4 weeks later,the teratomas were removed for HE staining and the differentiation of tissue was observed.Results:The iPSCs were successfully obtained from MEFs by piggyBac carrying Oct4,Sox2,Klf4,and c-Myc.The round or oval iPSCs clones were similar to ESCs with clear boundry and large dense nuleus.The iPSCs showed the normal karyotypic and expressed the marker genes (Oct4,Nanog and FGF4)and proteins (SSEA-1,Nanog and AP)of ESCs.Teratomas containing three germ layers were formed in NOD-SCID mice after tanspalantation of iPSCs.Conclusion:The iPSCs are reprogrammed from MEFs by piggyBac transposon with four transcription factors-Oct4,Sox2,Klf4 and c-Myc,and the iPSCs with normal karyotype possess the characteristics of ESCs.
ABSTRACT
BACKGROUND:In recent years a large number of studies have suggested that bone marrow mesenchymal stem cells can ease hyperglycemia of diabetic rats, but the related mechanism is unclear and controversial. OBJECTIVE:To investigate the relevant mechanism of bone marrow mesenchymal stem cells on pancreas microenvironment in vivo in diabetic rats. METHODS:Bone marrow mesenchymal stem cells were transfected with enhanced green fluorescent protein (EGFP) and administered to diabetic rats via the subcapsular pancreas. Blood glucose levels were monitored. The expressions of the key genes in islet development in these EGFP positive pancreatic cells were analyzed by Real-time quantitative PCR at different times. EGFP and insulin double-positive cells were detected by immunofluorescence. Flow cytometry was performed to analyze cellcycle and DNA ploidy. RESULTS AND CONCLUSION:Blood glucose levels were effectively reduced after transplantation. The expressions of the key genes in islet development reached their own peak values at different times after transplantation:Nestin at week 1, Nkx 2.2 at week 3, Pax 4 and Ngn 3 at week 4, insulin and glucagon at week 12, PDX-1 at week 8 until week 12. The cells double-positive for EGFP and insulin cells were observed. In the pancreas, EGFP positive cells at S+G 2/M phase were significantly increased, and there were no polyploid and aneuploid cells. In pancreas microenvironment, the bone marrow mesenchymal stem cells transplanted into the diabetic pancreas can differentiate into isletβ-like cells under gene control, but not through the fusion with tissue cells.
ABSTRACT
Epithelial-mesenchymal transition (EMT) is a major mechanism in tumor metastasis.As the key regulatory factor,Twist gene plays an important role in EMT,and it can be induced by radiotherapy,chemotherapy and a variety of cytokines.Researches show that tumor cells can get stem cell-like properties via EMT,which can lead to chemo-radiotherapy resistance,tumor angiogenesis and distant metastasis.EMT has a great influence on the prognosis of tumor,and it is expected to become an important target for tumor treatment.
ABSTRACT
Objective To investigate the immune regulatory effects of allogeneic bone marrowderived mesenchyrnal stem cells (MSCs) co-transplanted with islets. Methods The 18 diabetic mice were randomly divided into 3 groups: Diabetic group, without any transplantation; Islet transplantation group, in a sterile operation, with 10 μl purified islets (about 200 islets)transplantation to the left renal subcapsule of recipients; Islet + MSCs transplantation group, in addition to transplantation as the former group, 1 × 106 MSCs were given to the recipients via tail vein on 3, 2 and 0 days before islet transplantation. Blood glucose in recipient mice was monitored for 30consecutive days after transplantation. Pathological characteristics of left kidney were analyzed on the day 14 and 28 after transplantation. Th1/Th2, Tc1/Tc2, naive and memory T cells from peripheral blood and bone marrow-derived dendritic cells (DCs) were analyzed by multi-color flow cytometry.Results As compared with the islet transplantation group, blood glucose was significantly reduced,inflammatory cell infiltration decreased in the place of transplantation, graft survival prolonged, the number of Th1 and Tc1 cells was obviously reduced, the number of Th2 and Tc2 cells increased, the ratio of Th1/Th2 and Tc1/Tc2 cells was significantly decreased, the naive and memory T cells were significantly inhibited, the maturity of DCs and the secretion of interleukin-12 decreased in the islet transplantation group. Conclusion Through the immunomodulation on T-cell and DCs function,MSCs can alleviate graft verse host disease and prolong allograft survival.
ABSTRACT
Objective:To investigate the role of dendritic cells (DCs) in the anti-CD45RB antibody-induced immune tolerance,and the mechanism of immune tolerance induced by anti-CD45RB antibodies.Methods:DCs were induced by conventional methods(rmGM-CSF,IL-4 and LPS),different doses of anti-CD45RB antibodies were added in the induction process.Then,mature cells were harvested,and flow cytometry(FCM) was used to determine cell phenotypes,cycle and phagocytosis,ELISA method was performed to examine the concentration of IL-12 and the ability of T cell proliferation was observed by mixed lymphocyte culture.Results:The DCs preparation was shown a high expression of CD11C and CD83,a low expression of CD86,with strong proliferative and phagocytic capacity after treated with anti-CD45RB antibody.Its secretion of IL-12 was decreased,and it could less effectively stimulate T cell proliferation after treated with anti-CD45RB antibody.Conclusion:One of the mechanisms of anti-CD45RB monoclonal antibody-induced tolerance is to generate tolerogenic dendritic cells(tDCs),significantly inhibiting the proliferation of T cells.
ABSTRACT
OBJECTIVE In order to prevent and control the nosocomial infection effectively by hospital construction design scientifically.METHODS The theory and the practical application of hospital construction,were analyzed and discussed to prevent the nosocomial infection.RESULTS The hospital construction was fundamental in preventing and controlling nosocomial infection.It could control exogenous nosocomial infection.Through scientific and effective isolation,the hospital construction could help to control source of infection,cut off infection routin and protect the susceptible population.CONCLUSIONS Hospital construction design should conform to the principle of nosocomial infection precention and control.
ABSTRACT
OBJECTIVE To study the degree and regular of Aspergillus flavus air contamination in hospital.METHODS Some ambient air of different environment in our hospital was taken 5 times in one day of four seasons one year by using centrifugal air sampler,and then cultivated(using eumycete cultural methods),counted and analyzed.RESULTS A.flavus strain was collected in all sampling points in four seasons.The concentration of Aspergillus flavus in six standort was diverse from each other,and the highest was the out-patient clinic with 1238.9 CFU/m3.The concentration of Aspergillus flavus in each division of Medical Department was significant difference during four seasons(P0.05).The difference between internal medicine and external enviroment was significant between the first and the third season(P=0.022,P=0.039),but that of the second and the fouth season was not significant(P=0.022,P=0.624).CONCLUSIONS The contamination of Aspergillus flavus in hospital was severe.So it′s necessary to prevent the Aspergillus flavus infection and enhance the environmental control of susceptible population.
ABSTRACT
OBJECTIVE To explore the effect of the nanometer photocatalysis air disinfector.METHODS The air disinfection effect of nanometer photocatalyis air disinfectior JBL-400 series,such as the self-cycling movable,mosaic and attached to the wind gap air disinfectors,was detected in the simulating field trial and field trial in intensive care units,operating rooms and therapy rooms according to the Disinfection Technique Standards.RESULTS The kill ratio of self-cycling air disinfector in simulating trial was more than 99.9%.After constant air disinfection in the above three kinds of medical divisions,the total bacteria number of static state in these places could reach to the standard of area Ⅱ(≤200 CFU/m3),with 56.8-78.4% dissolution ratio of the natural bacteria.The total bacteria number of dynamic state in these places could reach to the standard of area Ⅱ or area Ⅲ.CONCLUSIONS The JBL-400 series air disinfector has diverse application forms,and disinfects quickly with good effects.It can be used in all kinds of medical divisions.